Reflex cutaneous vasoconstriction occurred during whole body cooling despite blockade of alpha- and beta-adrenergic receptors with yohimbine and propranolol (P<0.05), indicating a nonnoradrenergic mechanism.
Does whole body progressive cooling induce reflex cutaneous vasoconstriction via a nonnoradrenergic mechanism in men?
Reflex cutaneous vasoconstriction during whole-body cooling in humans involves a nonnoradrenergic mechanism, likely via a sympathetic cotransmitter.
p-value: p=< 0.05
We tested for a nonnoradrenergic mechanism of reflex cutaneous vasoconstriction with whole body progressive cooling in seven men. Forearm sites ( 0.05). CVC at saline sites fell significantly beginning at T(SK) of 33.4 +/- 0.01 degrees C (P <0.05). CVC at Yoh-PR sites was significantly reduced beginning at TSK of 33.0 +/- 0.01 degrees C (P < 0.05). After cooling, iontophoretic application of norepinephrine (NE) confirmed blockade of adrenergic receptors by Yoh-PR. Because the effects of NE were blocked at sites showing significant reflex vasoconstriction, a nonnoradrenergic mechanism in human skin is indicated, probably via a sympathetic cotransmitter.
Stephens et al. (Sun,) reported a other. Yohimbine plus propranolol vs. Intradermal saline was evaluated on Reduction in cutaneous vascular conductance (CVC) during cooling (p=< 0.05). Reflex cutaneous vasoconstriction occurred during whole body cooling despite blockade of alpha- and beta-adrenergic receptors with yohimbine and propranolol (P<0.05), indicating a nonnoradrenergic mechanism.